1. Field of the Invention
The present invention relates to an observation method for observing a sample by using a solid immersion lens, and the solid immersion lens.
2. Related Background Art
As a lens for magnifying a light image from a sample to be observed, a solid immersion lens (SIL) has been known. The SIL is a lens having a hemispherical form or a hyperhemispherical form known as Weierstrass sphere. When the SIL is placed in close contact with a surface of a sample, both the numerical aperture NA and magnification can be enlarged in the sample observation, which enables the observation with a high spatial resolution (see Japanese Patent Publication No. HEI 7-18806 and Japanese Patent Application Laid-Open No. 2002-189000).